A New Diverse Macrofossil Lagersttte from the Uppermost Ediacaran of Southwestern China

摘要

A new macrofossil Lagersttte was discovered from the uppermost Ediacaran Jiucheng Member at Jinning and Jiangchuan of the eastern Yunnan,yielding numerous diverse well-preserved thallophyte macrofossils.These include the previously-known representatives of vendobionts, Vendotaenia and Tyrasotaenia,and the biggish multicellular benthos such as Chuaria-like and Tawuia- like fossils,as well as Longfengshaniaceaens with diverse holdfast structures.There are still some other problematic macrofossils with peculiar configurations as well as uncertain relatives.The distinct dominance of the giant,unbranching thallophytes occasionally with hoidfast structures distinguishes this assemblage from the other Ediacaran macrofossil Lagerstttes in the Doushantuo Formation at Miaohe,Wenghni and Lantian,and the contemporary assemblage in the Shibantan Member of Dengying Formation,Yangtze Gorges area.This paper outlines the characteristics of some of the multicellular macrofossils from the Jiucheng Member at Jiangchuan.They include some macrofossils with different types of holdfast structure,larger Chuaria-like and Tawuia-like morphology and questionable affinities as well.The discovery of greater diverse macrofossil assemblages from the Jiucheng Member of eastern Yunnan has further indicated that an important diversification and evolutionary radiation of metaphytes took place in the latest Ediacaran time.This radiation of large- scale,benthic metaphyte along with phytoplankton was likely important contributors to the early Cambrian explosion of metazoans.